The Years of the Lamps began shortly after the creation of Arda by the Valar. After they entered the world, Arda was still lifeless and had no distinct geographical features. The initial shape of Arda, chosen by the Valar, was of a symmetrical continent lit by two lamps: one in the continent's north, and one in the south, made out of the misty light that veiled the barren ground. The Valar concentrated this light into two large lamps, Illuin and Ormal. The Vala Aulë forged great towers, one in the north, Helcar, and another in the south, Ringil. In the middle, where the light of the lamps mingled, the Valar dwelt at the island of Almaren.

The lamps were destroyed by an assault by Melkor. Arda was again darkened, and the lamps' fall spoiled the perfect symmetry of Arda's surface. Separate continents were created: Aman in the far West, Middle-earth in the middle, the Land of the Sun in the far East, and the Dark Land in the far South. At the site of the northern lamp was later the inland Sea of Helcar, of which Cuiviénen was a bay. The Years of the Trees begin after that.